Exam 44: Gas Exchange and Circulation

When you are jogging,your muscles are using more oxygen and releasing more carbon dioxide into the blood than when you are at home on the couch.Which of the following would occur during your jog?

Marine crabs have internal gills covered by an exoskeleton,and,because their whole body is covered by exoskeleton,they cannot expand their body enough to generate much negative pressure within the gill chambers to draw water in over their gills.Which of the following would serve to increase the efficiency of gas exchange by marine crabs?

Fick's law of diffusion describes the factors that influence the diffusion of respiratory gases across biological membranes like gills and lungs.Diffusion rate = k × A × (P₂ - P₁)/D.Natural selection is least likely to act upon which variable in Fick's law?

How does lymph differ between closed and open circulatory systems?

Which of the four muscular chambers of the human heart directly propels blood into the pulmonary circulation?

Which of the following functions is not a function of insect hemolymph?

A rabbit taken from a meadow near sea level and moved to a meadow high on a mountainside would have some trouble breathing.Why?

Figure 44.1 -On the ECG above,within which waveform would atrial relaxation occur?

Baroreceptors sensing a rapid increase in blood pressure will likely result in

Which of the following conditions would be the most likely result of an abnormally high blood pressure in an animal,like a reptile,possessing a closed circulatory system?

Figure 44.1 -On the ECG above,which waveform represents ventricular relaxation?

Why is it more difficult to obtain enough oxygen via respiration from water than from air?

Figure 44.1 -On the ECG above,which waveform represents electrical activity within the atria?

You are a physician,and see a patient who complains of abnormal fatigue during exercise.You find that the immediate problem is a buildup of carbon dioxide in the tissues.What is the most likely cause?

Which of the following statements supports the hypothesis that the bidirectional gas flow occurring in humans (air goes in and out through the same passages)is less efficient than the unidirectional flow in fish?

The oxygen content of water increases linearly with an increase in oxygen partial pressure,while the oxygen content of blood increases in a sigmoidal (S-shaped)fashion.Why?

Which of the following best describes the process of ventilation?

If other factors are equal,which of the following environments would have the highest level of dissolved oxygen?

A mutation results in a form of hemoglobin with binding sites for four molecules of oxygen but does not exhibit cooperative binding.Which of the following would result?

Which of the following result,either directly or indirectly,when carbonic anhydrase is functioning properly?